Sensor
A sensor is a device that detects, or senses, a signal or physical condition. Most sensors are electrical or electronic, although other types exist. A sensor is a type of transducer. Sensors are either direct indicating (e.g. a mercury thermometer or electrical meter) or are paired with an indicator (perhaps indirectly through an analog to digital converter, a computer and a display) so that the value sensed becomes human readable. Aside from other applications, sensors are heavily used in medicine, industry and robotics.
Since a signal is a form of energy, sensors can be classified according to the type of energy they detect. For example:
- light sensors: photocells, photodiodes, phototransistors, photo-electric tubes, CCDs, Nichols radiometer, Image sensor
- sound sensors: microphones, hydrophones, seismic sensors.
- temperature sensors: thermometers, thermocouples, temperature sensitive resistors (thermistors), bi-metal thermometers and thermostats
- heat sensors: bolometer, calorimeter
- radiation sensors: Geiger counter, dosimeter
- subatomic particle sensors: scintillometer, cloud chamber, bubble chamber
- electrical resistance sensors: ohmmeter, multimeter
- electrical current sensors: galvanometer, ammeter
- electrical voltage sensors leaf electroscope, voltmeter
- electrical power sensors watt hour meters
- magnetism sensors: magnetic compass, flux gate compass, magnetometer
- pressure sensors: barometer, barograph, pressure gauge, air speed indicator, rate of climb indicator, variometer
- gas and liquid flow sensors: anemometer, flow meter, gas meter, water meter
- motion sensors: radar gun, speedometer, tachometer, odometer, turn indicator
- orientation sensors: gyroscope, artificial horizon, ring laser gyroscope
- mechanical sensors: position sensor, selsyn, switch, strain gauge
- proximity sensor- A type of distance sensor but less sophisticated. Only detects a specific proximity. A combination of a photocell and LED or laser. Applications in cell phones, paper detector in photocopiers, auto power standby/shutdown mode in notebooks and other devices.
- distance sensor- A combination of a photocell and laser LED. Mainly in autofocus cameras, sophisticated binoculars and robotics.
- whisker sensor- A type of touch sensor and proximity sensor.
The human sensors are the senses.
See also
Links
- Federal Standard 1037C, August 7, 1996: transducer (http://www.its.bldrdoc.gov/fs-1037/dir-032/_4770.htm)
- American National Standard for Telecommunications - Telecom Glossary 2000: sensor (http://www.atis.org/tg2k/_sensor.html)
- SensEdu; how sensors work (http://www.sensedu.com/)
da:Sensor de:Sensor fr:Capteur it:Sensore nl:Sensor ja:センサ zh:传感器